Puyo Puyo Tsuu (ぷよぷよ通) or Puyo Puyo 2 is a puzzle game developed by Compile in 1994, initially released for Sega's System C-2 arcade board before being ported to other consoles (such as the Sega Mega Drive, Sega Game Gear, and Sega Saturn). It is the sequel to the Sega/Compile version of Puyo Puyo, whose path the entire series has followed to date.

The standalone game was exclusively released in Japan until 2000, when Sega ported it to the Neo Geo Pocket Color under the name Puyo Pop in the US/Europe (unrelated to the GBA Puyo PopMinna de Puyo Puyo) — making it the first Puyo Puyo game to be released outside Japan unaltered (and establishing the Puyo Puyo/Puyo Pop naming discretion still used today). It was also included as the Classic mode of Puyo Pop Fever and later rereleased on the Virtual Console's Import section (albeit untranslated).

Gameplay

While the 1992 release of Puyo Puyo is credited for introducing competitive play, the improvements made in Puyo Puyo Tsuu made it a gold standard for tournaments, and the basis for all Puyo Puyo releases going forward. Unlike its predecessors, no non-competitive single player modes exist in Tsuu (i.e. "practice" or "endless") - the player is always pitted against a human or AI opponent (an exception being the later Sega Saturn version, which brings these modes back).

Puyo Puyo Tsuu introduces a concept known as "sousai" (相殺), commonly translated as "offsetting" or "countering" as a form of defense against incoming ojama puyo. If, while ojama puyo are queued to land in your play area, you are able to pop puyo, the resulting ojama created in your turn will cancel out the ojama your queue. For example, if five ojama are queued and your pop creates four, you will only receive one ojama puyo. Furthermore, if in this situation you create six ojama puyo, your opponent will receive one instead.

While the sousai rule can be disabled, it typically leads to shorter games, as skilled players can both send ojama puyo to their opponent, and avoid receiving any ojama puyo themselves. Subsequently, this style of gameplay leans towards a need for large chains obtained within the shortest possible time. The scoring has also been revised so that the big points are only available to those who can create these large chains.

As with all Puyo Puyo titles, five different colours of puyo exist, however unlike its predecessors, Puyo Puyo Tsuu rarely uses all five colours at once. Instead it is more common for four colours to be used, which in turn leads to a greater chance of producing chains (Puyo Puyo Sun would later reduce this to three colours for earlier stages). As fewer colours in play usually leads to more popping, players are less likely to lose based on puyo placements alone.

With "Rule Henka" enabled, two new types of ojama puyo come into play. "Kata puyo" (固ぷよ), resembling ice blocks, are twice as strong as ojama (but are popped in the same way) and "tokuten puyo" (得点ぷよ) increase the player's score if popped. The "Rensa Shibari" option also allows players to dictate how many chains are needed to generate ojama puyo.

Also new to Tsuu is the "quick turn" (クイックターン) feature. If a falling pair of puyo is obstructed on both sides, rotating will cause the pair to flip, with the top puyo becoming the bottom and vice versa. Also, while previous Puyo Puyo ganes only show a preview of the next piece, Tsuu shows two upcoming pieces, theoretically allowing the player to plan further ahead.

Finally "zen keshi" (全消し) or "full erase" bonuses are awarded if the player manages to pop all the puyo in their play area. This in turn causes a significant amount of ojama (or tokuten) puyo to be sent to the opposing player after the next pop.

While the single player campaign is similar to 1992's Puyo Puyo, it is now less linear, with multiple stages of progession accessed only when the player has achived enough "rest points". Opponents are to some degree randomised, and given that each opponent uses different tactics, this means it is less likely two playthroughs will be the same. Furthermore some opponents only appear if the player deliberately scores too few rest points, or manages to level up without using any continues.

A unique technical feature to the Mega Drive version is a "voice" option. While sampled speech cannot be turned off during normal play, the player can opt for lower quality samples that do not interrupt the music.